Comparison of spin photocurrent in devices based on in-plane or out-of-plane magnetized CoFeB spin detectors

Xiaodi Xue (1, 2) , Laipan Zhu (1, 3) , Wei Huang (1, 4) , Xavier Marie (5) , Pierre Renucci (5) , Yu Liu (1, 6) , Yang Zhang (1, 6) , Xiaolin Zeng (1, 6) , Jing Wu (1, 6) , Bo Xu (1) , Zhanguo Wang (1) , Yonghai Chen (1, 6) , Weifeng Zhang (2) , Yuan Lu (7)

1 LSMS - Key Laboratory of Semiconductor Materials Science
2 Henan University
3 Beijing Institute of Nanoenergy and Nanosystems
4 Science and Technology on Monolithic Integrated Circuits and Modules Laboratory, Nanjing Electronic Devices Institute, Nanjing 210016, China
5 LPCNO - Laboratoire de physique et chimie des nano-objets
6 UCAS - University of Chinese Academy of Sciences [Beijing]
7 IJL - Institut Jean Lamour

We have measured a helicity-dependent photocurrent at zero external magnetic field in a device based on a semiconductor quantum well embedded in a p-in junction. The device is excited under vertical incidence with circularly polarized light. The spin filtering effect is evidenced in the temperature range 77-300 K owing to a CoFeB/MgO spin filter with out-of-plane magnetization in remanence. The helicity-dependent photocurrent is explored as a function of the temperature and bias. These characteristics are compared with those of a spin photocurrent device with in-plane magnetized CoFeB/MgO spin filter, excited under oblique incidence with circularly polarized light. In contrast to the in-plane spin filter device, the circularly polarized light asymmetry of the photocurrent in the out-of-plane device depends weakly on the external bias. The two devices are sensitive to the spin filtering of either the in-plane (S x) or out-of-plane (S z) photogenerated electron spin in the semiconductor quantum well. The helicity-dependent photocurrent results can be explained by the Dyakonov-Perel electron spin-relaxation mechanism. Our study reveals the giant spin relaxation anisotropy in III-V zinc-blende quantum wells in the presence of a vertical electric field.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Xiaodi Xue, Laipan Zhu, Wei Huang, Xavier Marie, Pierre Renucci, et al.. Comparison of spin photocurrent in devices based on in-plane or out-of-plane magnetized CoFeB spin detectors. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2019, 100, ⟨10.1103/PhysRevB.100.045417⟩. ⟨hal-02388090⟩